British actor Fletcher makes a terrific directing debut with this sharply told story of a family struggling to survive in a bleak environment. But this film is so full of hope that it thoroughly engages our emotions even when things get scary.

Since their mum left nine months earlier, 15-year-old Dean (Poulter) has been taking care of 11-year-old brother Jimmy (Williams) by working in construction at the Olympic park. But Jimmy is failing at school and getting increasingly involved with a gang of local drug dealers (Gregory, Maskell and Rheon). Then after eight years in prison, their dad Bill (Creed-Miles) comes home, realising that he must show some responsibility to keep his sons from being taken into care. But they don't know him, and he doesn't know anything about being a father.

Unlike in most movies set on grim British housing estates, Fletcher balances the danger with warmly drawn characters who are complex and engaging. At the centre, Creed-Miles is superb as Bill, a former wild boy trying to go straight, much to the annoyance of his former gang. So when he realises that they have co-opted his younger son, he struggles with what to do: merely associating with criminals is a violation of his parole, so rescuing Jimmy may risk everything.

Meanwhile, Poulter delivers yet another bristling performance as an angry young man trying to hold things together, more than a little annoyed that his long-lost dad is upsetting what he thinks is a workable life. Meanwhile, he's falling for Steph (Spencer), a young mother living with her drunken dad (Warren). And he's also annoyed that his dad brings home a woman (White) whose own life has taken a nasty turn.

Fletcher gives this the snap of real life, filling scenes with raw humour and a sense of dark menace that never feels cranked up for cinematic purposes. But then, it doesn't need to be: there's no quick solution for this fragile family. Even the helpful parole officer (Williams) and care worker (Winstone) carry an underlying threat. And it's through the detailed characterisations that this film manages to both surprise us and move us deeply.